SOURCE

let HunterUnion = {
        type: 'DOM',
        topics: Object.create(null),
        subscribe: function (topic, fn){
            if(!this.topics[topic]){
                  this.topics[topic] = [];  
            }
            this.topics[topic].push(fn);
        },
        publish: function (topic, money){
            if(!this.topics[topic])
                  return;
            for(let fn of this.topics[topic]){
                fn(money)
            }
        }
    }



function DOM (name, level) {
    this.name = name
    this.level = level
    this.list = []
}
 DOM.prototype.addListener = function (topic, fn){
        console.log(this.level + '猎人' + this.name + '订阅了狩猎' + topic + '的任务')
        HunterUnion.subscribe(topic, fn)
    }
DOM.prototype.publish = function (topic, money){
    console.log(this.level + '猎人' + this.name + '发布了狩猎' + topic + '的任务')
    HunterUnion.publish(topic, money)
}
let hunterMing = new DOM('小明', '黄金')
let hunterJin = new DOM('小金', '白银')
let hunterZhang = new DOM('小张', '黄金')
let hunterPeter = new DOM('Peter', '青铜')

hunterMing.addListener('tiger', money => {
    console.log('小明表示：' + (money > 200 ? '' : '暂时很忙，不能') + '给予帮助')
} )
hunterJin.addListener('tiger', function(){
    console.log('小金表示：给予帮助')
})
hunterZhang.addListener('tiger', function(){
    console.log('小张表示：给予帮助')
})

 hunterPeter.publish('tiger',198)